Combination of smartphone digital image colorimetry and UV-Vis spectrophotometry as detection systems with solidified floating organic drop microextraction as preconcentration method for the quantification of methyl red in wastewater samples.

In this study, a portable smartphone-based digital image colorimetric system (SDIC) was designed and integrated with a solidified floating organic drop microextraction method (SFODME) for the quantification of methyl red in textile wastewater samples. The RGB (red, green, and blue) data were evaluated for each captured image, and the green channel was selected for quantification due to its linear response for the analyte. Under optimal conditions, an acceptable linear range was recorded for the analyte.